We used TKs RSVP function. It did not send out an email to our guests (I don't know if this is an option somewhere). We sent our invitations with RSVP card that included the option of "or RSVP on our website XXXaddress".

@charlotte989875 how glitch is the RSVP on the knot?? We sent save the dates with our website on it out and I noticed a few people are now listed as declined. Most of these people I expected (friends that live states away) but my uncles entire family is listed as declined which my parents found odd and in their opinion rude. I was originally not going to send invites to the people who said they weren't coming but should I send it to my uncles family??

@charlotte989875 how glitch is the RSVP on the knot?? We sent save the dates with our website on it out and I noticed a few people are now listed as declined. Most of these people I expected (friends that live states away) but my uncles entire family is listed as declined which my parents found odd and in their opinion rude. I was originally not going to send invites to the people who said they weren't coming but should I send it to my uncles family??

Everyone who received a Save the Date needs to get an invitation, even if they've already RSVPed on your website "no". You never know what plans can change before your deadline and you'd be the rude one to not send an invitation after sending the STD. Declining a wedding isn't rude.